The existing flatbed trolley generally comprises a bearing frame, a handle, rotary frames, wheel carriers, casters and a rear lock seat. The handle of the existing flatbed trolley is usually parallel to the bearing frame when folded, and may be rotated and unfolded for 90 degrees to be perpendicular to the bearing frame when using. While the handle is unfolded, the handle will drive the rotary frame to drive the casters to rotate and unfold for 90 degrees to be perpendicular to the bearing frame. The flatbed trolley is pushed by holding the handle. The disadvantages of the existing flatbed trolley are that, when the handle is folded from a state perpendicular to the bearing frame to a state parallel to the bearing frame, it will also drive the rotary frame to drive the casters to fold to a position parallel to the bearing frame. When a cargo having a volume far beyond an area of the bearing frame is required to be put on the bearing frame, the handle in a state perpendicular to the bearing frame will often become an obstacle. If the handle is folded to be parallel to the bearing frame, the flatbed trolley cannot work.